IDEA-83969 code completion in switch/case: auto/unboxing not checked with code completion

java/java-impl/src/com/intellij/codeInsight/completion/JavaCompletionContributor.java

@@ -96,8 +96,8 @@ public class JavaCompletionContributor extends CompletionContributor {
         public boolean accepts(@NotNull PsiSwitchStatement psiSwitchStatement, ProcessingContext context) {
           final PsiExpression expression = psiSwitchStatement.getExpression();
           if(expression == null) return false;
-          final PsiType type = expression.getType();
-          return type instanceof PsiClassType;
+          PsiClass aClass = PsiUtil.resolveClassInClassTypeOnly(expression.getType());
+          return aClass != null && aClass.isEnum();
         }
       })));
   private static final ElementPattern<PsiElement> AFTER_NUMBER_LITERAL =

java/java-tests/testData/codeInsight/completion/normal/UnboxedConstantsInCase.java

@@ -0,0 +1,11 @@
+public class Demo {
+    void foo(Integer i){
+        switch(i) {
+            case Types.CH<caret>
+        }
+    }
+}
+
+interface Types {
+  int CHAR = 2;
+}

java/java-tests/testData/codeInsight/completion/normal/UnboxedConstantsInCase_after.java

@@ -0,0 +1,11 @@
+public class Demo {
+    void foo(Integer i){
+        switch(i) {
+            case Types.CHAR<caret>
+        }
+    }
+}
+
+interface Types {
+  int CHAR = 2;
+}

java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionTest.groovy

@@ -773,6 +773,7 @@ public class ListUtils {
 
   public void testSecondMethodParameter() throws Throwable { doTest(); }
   public void testReturnInCase() throws Throwable { doTest(); }
+  public void testUnboxedConstantsInCase() throws Throwable { doTest(); }
 
   public void testAnnotationWithoutValueMethod() throws Throwable {
     configureByFile(getTestName(false) + ".java");